Engine Rebuild AW11 MR2

[Alex170984]

Hi All,

My name is Alex and come from the UK.

I have been removing/stripping my red top 16v 4AGE since November last year and in the last few months, I have been putting it back together. I have never done anything like this before but have had help from my best mate and qualified car mechanic who successfully rebuilt his 4AGZE and converted his mk1a to SC, so in safe hands...

It's got to the stage where I have done the following:-

Reassemblied the entire bottom end with all new parts, excluding cranshaft and oil pump. I have replaced the old pistons with 81.5 oversize pistons, not toda or wiseco etc but unfortunately after I had bought my new pistons I found out my old ones were the low comp 9.4:1! But thankfully had bought the same compression but oversize.

I have replaced the main and big end bearings, main and big end bolts are now ARP, a new sump with oil return pipe (as the existing engine is from a corolla and didn't have this outlet).








The engine was bored out, honed to suit the new pistons. Degreased and had the crank polished. The head was degreased and had to be slightly skimmed due to an overheating incident earlier on last year. I am putting the head back together this week.



Above showing how it will look, but please not the rear backing plate is not attached - but it is now

Last night I unwrapped my camshafts from Cat Cams - 252/260 with 8.5/9.0mm lift - They will be put on this weekend along with my new Cometic Metal HG which is 1mm thick.





All I have left to buy is a pair of vernier pulleys and a lower cambelt cover as mine broke during the removal of the engine / engine parts.

Has anyone else used these cams before and what has been the outcome?

Thanks for reading. I could have written a lot more but its making my hand hurt!!

[gotzoom?]

Looks good. Can't help you with the cams, though. You used engine assembly lube or at least some oil on the bearings, right?

[Alex170984]

Of course

Don't know whether I should use running in oil or fully synthetic though for the first 500-1000 miles...

[yoshimitsuspeed]

You are going to change your oil a few times pretty shortly after getting it running.
For cost and healthy break in just run a standard cheap dino oil for the first couple changes. Once you are ready to run oil at standard recommended intervals switchover to the oil of your preference.

[gotzoom?]

I use the cheapest 10W40 dino oil I can find and I got a bottle of breakin additive from my local auto parts shop. Pour in the oil and additive per the directions on the bottle. Once I get the engine running, I immediately go to my favorite mountain road and drive the whole thing in 4th gear, paying attention to try and keep the revs between 1500 and 4000RPM. The idea is to lug the engine and create as much crankcase pressure as possible and force the rings into the cylinder walls to seat them. On freshly honed cylinders, you have a very short space of time to seat the rings. If you don't seat them properly, the engine will always burn oil. You will probably see oil smoke coming from the exhaust until they are seated. Once the rings are seated, the smoke will go away. After that, I change to a new oil filter (I always use Wix brand) and fresh cheapest 10W40 dino oil. I run that oil for 1000 miles, do another change and I run the oil that I intend to run going forward and change at 3000 mile increments.

[totta crolla]

Cat cams are good and I have had good results from mine by timing them by the lift at TDC method and the specs. are available from the Cat cams web site. (don't forget to allow for valve clearances when measuring lift)
You will likely need to fine tune them on a dyno.

[allencr]

...drive the whole thing in 4th gear, paying attention to try and keep the revs between 1500 and 4000RPM. The idea is to lug the engine...

This is EXACTLY what NOT to do.
google mototune or almost anywhere rather then the above.

[gotzoom?]

Err... are you trying to say not to use the Monotune method or to use it? I had actually never heard of this breakin method called Monotune before, but that is essentially how I break in engines and they run flawlessly. I'm not sure what your point is.

[yoshimitsuspeed]

Err... are you trying to say not to use the Monotune method or to use it? I had actually never heard of this breakin method called Monotune before, but that is essentially how I break in engines and they run flawlessly. I'm not sure what your point is.

The mototune method uses a short hard pull to seat the rings followed by a complete off throttle decel to cool and lubricate the cyls. You want short bursts moving through the power band.
Your method as you described it sounds like lugging it for an extended period. This would not be a good break in method.

[Alex170984]

I was given different advice a few years ago when I had another rebuilt engine. The advice I was given was to drive it slowly lol.

Then was told brisk acceleration and deacceleration through the power band was better.

Do I actually need adjustable pulleys? Could I get away with standard? There was no timing card with my cams...

[totta crolla]

You will get the best from the cams by using adjustable pulleys.
Easy to check if you need them by timing the cams using the lift at TDC method (no cam card required for this) and then looking to see where the standard timing marks end up on the factory pulleys.

Whereabouts in the U.K are you ?

[yoshimitsuspeed]

I was given different advice a few years ago when I had another rebuilt engine. The advice I was given was to drive it slowly lol.

The soft break in is a very traditional method and has probably been around the longest. Most OEMs still recommend using this break in method. My sister just got here WRX rebuild at Subaru and they told her not to get on boost or rev it over 3500 for quite a while. It made me laugh.
People will argue which is better for ages to come.
Personally I agree with the science behind the method described by mototune and always use it.
The only motor I have really had the opportunity to watch go through a couple cycles is my CR250. 2 strokes notoriously loose compression and need top end rebuilds frequently.
My first top end rebuild used the traditional easy break in. Warmed it up and let it idle several times and then babied it for the first couple hours of riding.
My second rebuild I let it warm up fully one time, checked for leaks, made sure everything was good and then let it cool down. Second time I started it up, let it warm up till the jug was nice and warm and then went out and got on it quick and hard. Did short pulls in lower gears up to near redline and then a coast back down to low RPMs. I did that around the block once and called it good. When I went riding I rode it like normal from the get go. I put about twice as much time on that piston as I did the first one and it still had the same compression it did when I put it in. At least up to the day I grenaded the bottom end playing with jetting on my new engine dyno lol.

[Alex170984]

You will get the best from the cams by using adjustable pulleys.
Easy to check if you need them by timing the cams using the lift at TDC method (no cam card required for this) and then looking to see where the standard timing marks end up on the factory pulleys.

Whereabouts in the U.K are you ?

Im in Essex mate - also a member of the AE86 ORG and IMOC.

Problem with the timing is going to be with my crank pulley - it's aluminium and brand new. I've also got a Corolla block so there is no timing pin either. I may just mark up the new pulley with markings from the old crank pulley.

I'm also in need of a bottom cambelt cover as well - you got one spare?

[totta crolla]

I might have a bottom cam belt cover for you.
Are you the same alex that had an ecu plug for me ?
If so maybe we could do a swap if I can find a cover ?

I would have been happy to help you out but Essex is maybe a bit far, I'm in Oxfordshire....

[Alex170984]

I am the same Alex indeed

I'll cut that plug off for you tonight and post it on Saturday as i'm on holiday as of Sunday through til the next Sunday.

Have you got an email address I can get you on just to confirm it's the right plug?

Swap sounds Good -

Alex

[totta crolla]

PM'd

There is also a timing mark on the cam belt crank pulley:

http://opc.mr2oc.com/online_parts_catal ... gmarks.gif

[Alex170984]

hello mate,

I can't seem to reply to your PM

don't worry about postage fees, unless you cannot find the lower cambelt cover - the postage will be about the same anyway, so just a straight swap with no money involved would be fine by me...

[oldeskewltoy]

check for coil bind with those camshafts

the mr2 pointer is the timing tensioner bolt... just buy an MR2 one... 90109-10148 - likely under $2.00

When setting camshaft timing... you really NEED to KNOW TDC......